Doreen Lawrence has spoken out against the government's attempt to repeal section 3 of the Equality Act 2006. Photograph: Peter Macdiarmid/Getty Images

Our Tory-led government will today mark the 20th anniversary of the racist murder of Stephen Lawrence by trying to remove a key piece of equality legislation that flowed from the Macpherson report.

As a currency, the phrase "If you thought the Tories couldn't stoop any lower…" would now be so devalued we would be lugging it round in wheelbarrows. This vote on whether to repeal a section of the Equality Act 2006 is, of course, simply unfortunate timing. But it doesn't sit alone; it fits neatly into a political project to roll back years of progress.

Indeed, under the failing austerity programme that PCS members and others are fighting on a daily basis, the government has imposed a near 70% budget cut on the Equality and Human Rights Commission. At the same time, it has sent a clear signal that legal requirements to ensure public bodies build equality into every stage of their policy and decision-making processes need not be taken as seriously as before.

The technical issue is this: later this afternoon there will be a vote in the House of Lords on whether to repeal section 3 of the Act via a clause in the government's enterprise and regulatory reform bill. Known as the general equality duty, section 3 seeks to ensure all people have an equal opportunity to participate in society free from discrimination.

Those against repeal include Stephen's heroic campaigning mother, Doreen, who understands the issues all too well; the public, who in the government's consultation responded by six-to-one in favour of keeping the duty; parliament's joint committee on human rights; and the European Commission. Those in favour: our government. The EHRC – which had supported scrapping the duty despite deriving its powers from the Equality Act – made an 11th-hour U-turn last week to declare the government had failed to make its case.

The implications are grave and far-reaching. The duty extends beyond government into wider society, and removing it could, among other things, jeopardise our human rights status in the eyes of the United Nations.

At street level, it is about the kind of society we want to live in. Ending prejudice and discrimination is not just about changing people's perceptions and attitudes. It is about constructing a society where the barriers in front of minorities and vulnerable people that have been erected both consciously and subconsciously, are permanently removed.

The impact is demonstrable. When we asked our union representatives in the civil service what effect equality law had had, one noted: "It has allowed us to request suitable adjustments to ensure disabled people perform at their best."

Others are reporting that civil service employers are starting to only pay lip service to equality, bolting on the bare minimum once a policy decision has been made. Rather than equality of opportunity being an afterthought, it ought to be mainstream, routine and rigorous. And to ensure this, the EHRC needs to be much stronger, not weaker.

Society has moved on in the 20 years since Stephen was murdered, but nowhere near far enough and continued progress is not inevitable. In fact, it is under threat from Tory ideologues who would rather demonise the unemployed, sick and disabled, and cut their benefits, instead of creating jobs and opportunities for them. Their poisonous "skivers" rhetoric leaches into society, as figures show disability hate crime is up 18% to the highest since records began.

We are hearing from our reps that some disabled workers are being actively targeted on performance and attendance grounds, as government departments strive to meet arbitrary headcount figures demanded by ministers' spending cuts – imposed cuts that have led civil servants to begin a three-month campaign of industrial action.

The unemployment rate of young black people increased from 28% in 2008 to 47% in 2011. Only around half of all disabled people are in employment and, among them, those with mental health problems have the lowest employment rate. These figures tell us nothing about the characters of the people involved, they are symptoms of an unequal society, where access to and success in education, training and employment are marred by institutional discrimination that we have failed to eradicate since Macpherson. Twenty years to the day since racist thugs took Stephen Lawrence's life, it would be a sick tribute indeed if this latest slice of Tory ideology was allowed to pass.

The murder of Stephen Lawrence shocked Britain and forced the country to take a hard look at itself. On the 20th anniversary of his death we ask Robert Beckford, Helen Oyeyemi, Diane Abbott, Ashley Walters, Kele Okereke and Estelle what impact his death had on them and society